Method and means for perforating well casings



Aug. i3, i940- J. w. MaccLATcHlE METHOD AND MEANS FOR PERFORATING WELL CASINGS Filed April 13, 1937v 5 Sheets-Sheet l JOHN W. MACCLATCHIE lAug. 13, 1940. J, w, MaccLA'rcHlE 2,210,983

METHOD AND MEANS FOR PERFORATING WELL CASI-NGS Filed April 13, 1957 3 Sheets-Sheet 2 W. MACCLATCHIE Br 30 i1- Q- @ww-MMM# Aug. 13, 1940. J. w. MaccLA'rcHlE METHOD AND MEANS Fon PERFORMING WELL cAsINGs s.sheets'sneet` :s

Filed April 1s, 1957 JOHN W. MACCLATCHIE Patented Ang. 13, 1940 UNITED STATES 'PATENT OFFICE METHOD AND MEANS FOB PERFORATING WELL CASINGS 8 Claims.

The general object of the invention is to provide a means by which a casing perforator of the gun type can be operated by a drill string or a cable.

A further object of the invention is to provide an improved gun'perforator which can be operated by means of a drill string or a cable, and by means of which a well casing can be perforated as desired without removing the gun from the well.

A further object of the invention is to provide a gun perforator which is simple in construction, which is capable of positive action by mechanical means, and which. cannot be accidentally red.

A further object of the invention is to providel a gun perforator by means of which the well casing can be perforated at any predetermined intervals as desired.

A further object of the invention is to provide a gun perforator which is provided with sealing means to prevent any fluid from entering the gun mechanism.

A further object of the invention is to provide a gun perforator in which the cartridges are carried by a traveling belt.

A further object of the invention is to provide a novel means of rotating part of the gun perforator while the remainder of the gun remains stationary in the well casing which movement causes a magazine belt to travel and the gun mechanism to operate.

A further object of the invention is to provide a means of allowing fluid to flow from the well while the casing is being perforated, and means for controlling said ow.

Other objects and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawings in which an example of the invention is shown, and wherein:

Figure l is a central vertical section view through the improved device taken through the line I-I of Figure 2.

Figure 2 is a section taken on line 2-2 of Figure 1.

Figure 3 is an enlarged fragmentary section showing theY firing mechanism and the sealing means.

Figure 4 is a section taken on line 4-4 of Figure 3,

Figure 5 is a central vertical view, partly in section, similar to the lower portion of Figure 1 showing the gun in firing condition.

Figure 6 is a central vertical view similar to (Cl. 16d- 0.5)

the upper portion of Figure 1 showing the upper safety means in inoperative position.

Figure 7 is a vertical section of a modification h f my invention, showing the gun in iiring posiion.v

Figure 8 is a section taken along the line 8 8 of Figure 7, showing the gun after one complete rmg operation.

Referring to the drawings by reference characters the improved gun perforator is indicated l generally at 2, and comprises a mainl body 3 and a head 4.

The upper part of the body 3 is provided with a drill pipe joint 5 and the head 4 is provided with friction springs 6 which are adapted to u keep .the head 4 from turning around when the gun 1s in ring operation. The lower endsl of the springs 6 are secured to the head 4 by means of screws and the upper ends are supported by a.

ring through which the body is free to slide and 20 rotate.

Threaded in the head 4 is a ring 'I which is provided with a flange 8 at its upper end. The

under slde of the ange 8 is provided with teeth 9 which are adapted to engage withteeth I0 25 of iiange II which is formed on the bottom of a gear ring I2 as shown in Figure 5. The gear ring I2 is supported in the lower end of the body 3 by flange I3 which rests oikantifriction bearings I4. The anti-friction bearings I4 are sup- 30 ported by a ilange ring I5 which is threaded nthidnzthe body 3 as indicated at I6 in Figures The gear ring I2 is adapted to be lockedto y the head 4 when the teeth 9 and I0 are in mesh 35 sprocket 2| is mounted in the upper part of the 40 body 3. A magazine belt 22 is mounted around the sprockets 20 and 2| andis adapted .to be driven by the sprocket 20 and to be held taut around said sprockets in any suitable manner such as by means of a spring 23 and a shoe 24.

The magazine belt consists of a plurality of links 25, which are adapted to be connected together by any suitable means, such as pins as' shown in Figure 3. Each link consists of a body 5 which is chambered to receive a cartridge, and formed on each body adjacent the cartridge opening 26 is a trigger projection 21. Each cartridge opening 26 is provided with a snap spring 28 which is adapted to snap into the groove of a 55 shcll and hold the cartridge -ln place when lnscrted in the cartridge opening 26.

A firing block is mounted in the body 3 and is provided with a barrel opening 3| which is in alinement with a corresponding barrel opening 32 in the body 3. Formed in the firing block 30 on the opposite side of the barrel opening 3| ls a firing pin opening 33. Mounted on this opening 33 is a hammer member shown as comprising a ring pin arm 34 which has a firing pin 35 normally suitated in axial alinement with the barrel opening 3|. The ring pin 35 is forced inward toward the cartridges in the belt by means of spring 36 which is supported around the pin 31 between the end of the hammer member and the inside wall of the body. The outer end of the pin 31 is provided with a recess which is threaded as indicated at 38 in Figure 3, which vthreads are adapted to be engaged by a suitable wrench (not shown) so that the firing pin arm can be drawn toward the wall of the body 3 and out 4of contact with the trigger projections 21 while the gun is being loaded.

As the magazine belt 22 travels, the trigger projection 21 is adapted to force the firing pin 35 out und snap back to explode the cartridge and force the bullet through the barrel openings 3| and 32 and perforate the casing. Mounted on the ring block 30, and surrounding the head of the barrel opening 3| is a sealing means 39, which may be in the form of a rubber washer or the like and is adapted to seal oi fluid and thereby prevent uid from entering the gun mechanism.

As shown in detail in Figure 4, wiping means 40 are provided above and below the barrel openings 3| and 32, to seal ofi aroun'd the magazine belt 22 and prevent any fluid from entering the gun mechanism. This means may consist of tension springs 4| which are mounted to plates 42 and thereby force the rubber wipers 43 against the magazine belt 22.

The drill pipe joint 5 is provided with a piston 46 which is held in inoperative position by means of springs 41 and which is adapted to trip a safety pin 48 when pressure is exerted on said piston by means of a go-devil, fluid pressure or other means. The safety pin 48 is connected to a wedge 49 which is adapted to engage the magazine belt 22 and prevent the belt from traveling, as shown in detail in Figure l, As shown in Figure 6, the drill pipe joint may also be provided with a ball bearing valve 50.

yThe body 3 is also provided with removable plugs 5| and 52and 53 in order to provide a means of loading and unloading the magazine belt 22.

In order to condition the gun for operation the plugs 5|, 52 and 53 are removed. By means of a suitable wrench (not shown) which engages the threads 38, the pin 31, ring pin arm 34 and the tiring pin 35 are drawn toward the wall of the body and out of engagement with the trigger projections 21 as they pass by, and held in said retracted position by any convenient means. Before being placed in a cartridge receiving opening 20, each cartridge 55 is provided with a sealing means 56, which may be in the form of a rubber washer, to seal off uid and which may be mounted on the bullet as shown in Figure 3. The magazine belt 22 is loaded and the cartridges are held in place by means of the snap springs 23. After the loading operation is completed, the

pin 31 is slowly moved to the position shown inV Figure 3, and plugs 5|, 52 and 53 are inserted in the body 3 for sealing purposes.

The gun is then lowered into the well casing by means oi the drill pipe to the location Where it is desired to perforate the casing. During this operation the gun is in the position shown in Figures land 2, with the wedge 49 in locking engagement with the magazine belt 22, and the head 4 free to turn with the body 3 due to the fact that the teeth 9 and l0 are not in engagement. 1n this way it will be seen that the gun cannot be accidentally red, thus providing ain additional safety means to the wedge means 49.

When the gun has been lowered to the desired location, the dril1 pipe is raised a short distance forcing the teeth 9 and |0 into engagement and thereby locking the head 4 to the gear ring I2, as shown in Figure 5.

The upper safety means is then released by means of a go-devil or other pressure means exerted against the piston 46 which forces the piston 46 to trip the safety pin 48 and thereby release the wedge 49 from engagement with the magazine belt 22 as shown in Figure 6,

The gun is now set for firing operation which is accomplished by rotation of the drill string. As the drill string is rotated, the body 3 turns but the head 4 remains stationary due to the action of the friction springs 6 against the well casing. As the drill string is rotated, the stationary gear ring |2,in the head 4 drives the gear I8 as it travels around with the body and thereby causes the sprocket 20 to drive the magazine belt 22. As

the belt 22 travels, the trigger projection 21 forces the firing pin 33 outward and as the upper edge of the trigger projection 21 clears the hammer, the spring 36 forces the firing pin 35 to snap back against the cap which explodes the cartridge sending the bullet through the barrels 3| and 32 and perforating the Well casing. The gun mechanism can be made so that it will fire four or any other desired number of times during one complete revolution of the body. The body is rotated once, and then raised a distance equal to the desired distance between the holes and then given another complete revolution.

These operations may be repeated until the casing is perforated as desired.

The valve 50 allows the fluid in the well to'flow out through the drill pipe while the gun is in the casing, but prevents the fluid from ilowing back from the drill pipe when pressure is exerted on the piston 46.` A blowout preventer, such as described in Patent No. 1,708,316 granted April 9, 1929, may be mounted on the top of the drill pipe, which is adapted to control the oW of the uid through the drill pipe, and thereby prevent bloW-outs in the event that the bullets perforate high pressure areas.

In the modification of my invention shown in Figures 7 and 8, the gun |00 is adapted to be operated by means of a cable. The construction of the upper part |0| of the gun |00 is exactly the same as the upper part 3 of the gun 2. However, the construction of the head |02 is different from that of, the head 4.

The head |02 is provided with friction springs |03 and an annular cup- |04, which may be made of rubber or any other resilient material, which are adapted to hold the head |02 against movement when the gun is in ring operation.

Mounted in the lower end of head |02 and rigidly secured thereto is a jack stemV |05, the threads |05@ of which are adapted to be engaged by jack stem teeth |06, which are forced into engagement with the jack-stem threads |a by means of springs |01, which are disposed between the jack stem threads |05@ and the wall of the head |02. A gear ring pin |08 is mounted in 'the jack stem |05 and is adapted to slide therein,

straddling a pin |09 which prevents the gear ring pin |08 from moving horizontally with respect to the jack stem thread |05a.

The upper end of the gear ring pin |08 is secured to a gea-r ring ||0 which is supported in the lower end of body |0| by meains of a ange The flange vis mounted on antifriction bearings ||2, which are supported by a supporting sleeve ||3 which is threaded within the body |0| as indicated at ||4 in Figure '7. The gear ring ||0 is adapted to mesh with the gear I0.

The gun is also provided with a safety device which is adapted to be released by a go-devil or other pressure means, similar to the safety device described in connection with the gun 2. Y

The gun |00 is conditioned for ring operation as described in connection with the gun I0, and is then lowered in safety position to the location when the perforations are desired. While the gun is being lowered it is in the position shown Figure 7.

The safety mechanism is then released and the cable is raised a sufficient distance to allow for vthe complete operation of the jack stem. During this operation, the -head |02 of the gun remains stationary due to the action of the springs |03 which prevent the head from rotating and the cups |04 which prevent the head from raising in the well. As the body |0| is raised, it rotates in the well casing due to the body traveling up the jack stem thread, causing the gear I8 to sired, and so that the gun will re four or any other desired number of times during one cornplete revolution of the body.

After the flring operation, the head of the gun is raised the desired distance betweenthe perforations. As the gun is raised the capacity of the cup is exceeded, due to the weight of the uid in the well, which forces the cup into the reverse position indicated in dotted lines in Figure 7.

In order to condition the gun for ring again, the cable is released until the head of the gun is again in the position shown in Figure '7. During the releasing operation, the jack thread teeth |06 snap over the threads of jack stem threads |050, due to the tapered surfaces of the jack thread teeth as shown in the drawings and the capacity of the cup is again exceeded, which forces the cup into its normal position shown in Figure 8.

The foregoing operations are continued until the casing has been perforated as desired without the necessity of removing the gun from the well casing.

Although I have described my invention with respect to certain particular embodiments thereof, nevertheless I do not desire to be limited to the particular details shown and described except as clearly specified in the appended claims, since many changes, modifications andv substitutions may be made without departing from my invention in its broader aspects, which may be found useful in many other applications thereof.

I claim:

1. A method of perforating well casing in place in a well hole which comprises lowering a gun down the Well casing to the desired location by means of the drill string, and then discharging the gun by rotation of the drill string.

2. A method of perforating well casing'in place in a well hole which comprises lowering a gun down the well casing to the desired location by means of the drill string, discharging the gun by means of rotating the drill string, raising the drill string the desired distance between the perforations, again discharging the gun by means of rotating the drill string, and repeating said last mentioned operations until the casing has been perforated as desired.

3. A method of perforating well casing in place in a well hole which comprises lowering a gun provided with a safety mechanism down the well casing, by means of the drill string, releasing the safety mechanism after the gun has been lowered to the desired location, and then ring the gun by means of the drill string.

4. A mehtod of perforating well casing in place in a well hole which comprises lowering a gun provided with a safety mechanism down the well casing by means of a cable, releasing the safety mechanism after the gun has been lowered to the desired location, and then discharging the gun by raising the cable.

5. A method of perforating well casing in place in a well hole which comprises lowering a gun provided with a safety mechanism down the well casing by means of a cable, releasing the safety mechanism after the gun has been lowered to the desired location, firing the gun a predetermined number of times by raising the cable, raising the cable after the ring operation the desired distance between the perforations, lowerling the gun to recondition the gun for firing operation and repeating the last three operations until the casing has been perforated as desired.

6. A method of perforating well casing in place in a well hole which comprises lowering a gun down the well casing to the desired location by means of the drill string, discharging the gun by rotation of the drill string, and controlling the flow of the uid from the well during the perforating operation.

7. A method of perforating well casing in place in a well hole which comprises lowering a gun provided with a safety mechanism down the well casing by means of a cable, releasing the safety mechanism after the gun has been lowered to the desired location, and then discharging the gun by vertical movement of the cable.

8. A method of perforating well casing in place in a well hole which comprises lowering a gun down the well casing to the desired location by means of a cable, discharging the gun by vertical movement of the cable, and controlling the ilow of the fluid from the well duringA the perforating operation.

JOHN W. MACCIATCHIE. 

